Thursday, July 15, 2004

"Geographic maps are a useful analogy for how we study genomes. If you were given a detailed map of London, you could learn a lot about what defines a large cosmopolitan city. You would see a large number of apartments, shops, and restaurants and might reasonably conclude that these are essential for life in the city. But you could not assess the relative importance of unique features like Buckingham Palace or the Brick Lane street market.

Things would be clearer if you were also given a detailed map of Paris. That too has apartments, shops, and restaurants, confirming your earlier hypothesis. It also has street markets, so perhaps those are an important, albeit secondary, aspect of city life. In contrast, Paris has no "active" royal palaces. Why not? One interpretation might be that Buckingham Palace is an important feature that distinguishes London from other cities. Another might be that a royal family has no function whatsoever in a modern society and survives in London merely as an evolutionary remnant. "